1. Both parties to an economic contract have to pay stamp duty, and the stamp duty is paid in full. 2. If the parties to an economic contract involve more than two parties, but more than two parties, all parties are taxpayers and must pay stamp duty. 3. However, if there are witnesses, guarantors and appraisers in the contract, they don't need to pay stamp duty. 4. In addition to the written form, if the taxable voucher is signed in electronic form, the stamp duty shall also be paid as required.